office, couldn't really speak, was standing there mumbling, sort of gibberish, when the secretary said, don, are you okay? but had he not been around someone else, it might have been a disaster. now we're being able to see warning signs of this through text messages. how can we really utilize this? >> i think that's a great point. a large proportion of strokes affect language functions, bless it's the ability to speak or understand language. and as communication becomes more electronic, as we're seeing with text messages and e-mails, et cetera, we're going to see a larger proportion of people who are having trouble with language that is being manifest in the text messages and e-mails they're sunning. and so in the setting of text message, the problem may be as we see here, that the text messages were being sent in a way that didn't make sense, a language problem in that sense, and you could also have text messages that you're receiving and unable to understand. >> clayton: there is a warning sign of stroke test that people should be aware of out there. take us through this. it's called the